FDA Grants Fast Track Designation to Rilzabrutinib for Treatment of ITP

The FDA has granted fast track designation (FTD) to rilzabrutinib, an oral investigational Bruton’s tyrosine kinase (BTK) inhibitor, for the treatment of patients with immune thrombocytopenia (ITP), according to Sanofi, the developer of the agent.

Additionally, following the observation of positive phase 1/2 study results, the company has also initiated a phase 3 study evaluating rilzabrutinib for ITP.

Rilzabrutinib is an oral, reversible covalent, BTK inhibitor being investigated for the treatment of immune mediated diseases. BTK is involved in innate and adaptive immune responses and is a signaling molecule found in immune mediated diseases.

"By awarding fast track designation to rilzabrutinib, an investigational candidate for the treatment of ITP, the FDA has recognized rilzabrutinib's potential to meaningfully improve outcomes for patients with this debilitating disease. This is an excellent acknowledgement as we initiate our phase 3 study,” Dolca Thomas, chief medical officer of Principia, a Sanofi company, said in a press release. “FTD is designed to facilitate the development and expedite the review of investigational treatments that demonstrate the potential to address unmet medical needs in serious or life-threatening conditions.”

In October 2018, rilzabrutinib also received orphan drug designation from the FDA for the treatment of ITP.

Thus far, rilzabrutinib has demonstrated an ability to block inflammatory immune cells, eliminate autoantibody destructive signalling, and prevent new autoantibody production without depleting B cells. Moreover, Sanofi indicated that rilzabrutinib has the potential to target the underlying disease pathogenesis and has not been shown to alter platelet aggregation. However, the clinical significance of these mechanisms is still currently under investigation and its safety and efficacy have not been reviewed by any regulatory authority.

In addition to being studied for the treatment of ITP, rilzabrutinib is being investigated in a phase 3 trial for pemphigus, an immune mediated disease characterized by blisters in mucous membranes and skin. In addition, a phase 2 study in the autoimmune condition IgG4 disease has also been initiated.

Reference:

Rilzabrutinib granted FDA Fast Track Designation for treatment of immune thrombocytopenia [news release]. Paris. Published November 18, 2020. Accessed November 18, 2020. https://www.sanofi.com/en/media-room/press-releases/2020/2020-11-18-07-15-00